This invention relates generally to the field of craniomaxillofacial distraction osteogenesis devices for treatment of craniofacial anomalies wherein a distractive force is to applied to portions of the craniofacial skeleton, mandible or maxila of a patient, the device being worn by the patient for an extended period of time such that relatively minor adjustments may be made in order to gradually effect osteogenesis.
Prior art fixation devices directed at the treatment of craniofacial anomalies, LeFort I mid-face asymmetry, maxillary and mid-face skeletal hypoplasia, mandibular hypoplasia, and similar conditions through distraction osteogenesis are known, the common such device being referred to as a halo fixation or distraction device. The term halo comes from the generally ring-shaped or U-shaped frame member that is fixated about the head of the patient. The halo is mounted to the head by a plurality of fixation screws that are tightened against the skull of the patient. The halo thus provides a support framework to which are attached the distraction means. While this method is effective in providing a fixed mounting of the device to the patient where relative movement between the halo and the patient's head in precluded, with relatively low pain and discomfort from the fixation screws, in young patients or with certain conditions the bone may not be strong enough to use fixation screws or cranial pins. Where internal bone fixation means are utilized, a second operation to remove the distraction apparatus is required. In addition, the visual presentation of the halo device is not pleasing.
It is an object of this invention to provide a craniomaxillofacial distraction osteogenesis device wherein the inherent problems associated with the halo devices are obviated by providing head mounting means for supporting the distraction means that does not utilize a ring-like or U-shaped frame mounted onto the head of a patient by fixation screws or pins, wherein instead the head mounting means comprises a helmet-type device, whether a full helmet, an open-top helmet, a shell or a cranial band, such that the compressive forces necessary to retain the helmet and the device on the patient's head in a fixed manner are broadly distributed about the head of the patient. It is a further object to provide such a device wherein the helmet is adjustable in configuration for size, shape and comfort, or wherein the helmet can be custom fitted to match the configuration of the patient's head. It is a further object to provide such a device wherein the distraction means can be attached to the helmet mid-face, laterally over the temporal or mandible area, or at other desired locations. These objects, in addition to objects not expressly stated here, are achieved by providing a device as disclosed below.